Electronic components are rapidly increasing in performance and miniaturization, due in part to tremendous competition and market demands. This, in turn, has required an increase in electronic board component contact densities. A variety of high-density socket technologies have resulted.
One of the more attractive socket technologies now commonly in use is a Land Grid Array (LGA) socket. As opposed to other socket technologies, LGA sockets typically do not require soldering when attaching the socket to a circuit board or other electronic module. Instead, an electrical connection is established through pad-to-pad contact by clamping the IC device to the circuit board through an intervening LGA socket having compliant, coplanarity-maintaining contacts.
FIG. 1 is a schematic of an exploded LGA socket assembly 100. A LGA socket 106 is compressed between a circuit board 102 and an electronic module 114 to achieve an electrical connection via forces 112. The LGA socket 106 includes a plurality of small, uniformly shaped contacts 108 that are typically arranged in a dense rectangular array. Each contact 108 is double-sided and electrically coupled to corresponding contacts 110 on the circuit board 102 and electronic module 114.
Due to their small size, each LGA contact has limited current carrying capability. Consequently, applications often require that more than one contact be used to transfer high current, such as power. This results in an increase in the number of contacts needed, increasing the size of the LGA socket and introducing various mechanical challenges.
For example, controlling flatness becomes more of an issue as the number of contacts on the LGA socket increases. Due to the flexible nature of one or more of the surfaces involved, warpage may be induced when applying the compressive force. Poor electrical connections between the socket and the first and/or second surfaces may result.
Another concern that will be encountered as devices become faster is the effects of electromagnetic interference (EMI). In particular, as the operating frequency of devices increase, grounding between devices and circuit boards becomes critical for EMI containment.